.u-meteor {
    width: 188px; height: 187px;
    background-image: url('./image/meteor.png');
    background-size: 100% 100%;
    position: absolute; top: 0; right: 0;
    &.l1 {
      left: 300px;
      animation: meteor 1.5s linear infinite;
    }
    &.l2 {
      right: -300px;
      animation: meteor 3s linear infinite;
    }
    &.l3 {
      right: -500px;
      animation: meteor 1.5s linear infinite;
    }
    &.l4 {
      right: 0;
      animation: meteor 3s linear infinite;
    }
    &.l5 {
      left: 400px;
      animation: meteor 4s linear infinite;
    }
    &.l6 {
      left: 50%;
      animation: meteor 4s linear infinite;
    }
  }
  .u-stars {
    width: 30px; height: 30px;
    background-image: url('./image/stars.png');
    background-size: 100% 100%;
    position: absolute;
    animation: flashing 3s linear infinite;
  }
  // 流星
@keyframes meteor {
    0% {
      transform: translate(100px, -100px);
    }
    100% {
      transform: translate(-100vh, 100vh);
      opacity: 0;
    }
  }
  // 星星动画
@keyframes flashing {
  0% {
    opacity: 0;
  }
  50% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}